In recent years, an image display device which is used in a state of being worn on a body of a viewer such as a head mounted display is provided as a wearable information device. For example, PTL 1 which is described below discloses a display device which is provided with a first two-dimensional light scanning device, a second two-dimensional light scanning device, a semi-transmitting reflecting device, and a reflecting device. In the display device, images which are generated by each of the first two-dimensional light scanning device and the second two-dimensional light scanning device are combined by the semi-transmitting reflecting device, and the combined image is projected into the eyes of the viewer by the reflecting device. PTL 1 further describes that it is possible to configure a display device which may be looked through by using a holographic lens or the like in the reflecting device.
PTL 2 which is described below describes an image display device which is provided with an eyeglass lens, a first curved surface mirror and a second curved surface mirror which are formed on each of left and right portions of a face-side concave curved surface of the eyeglass lens, and a light scanner which outputs a scanning light beam. In the image display device, the scanning light beam which is output from the light scanner is sequentially reflected by the first curved surface mirror and the second curved surface mirror, and is projected into the eyes of the viewer.
The image display device is used embedded in general eyeglasses, and the viewer is capable of viewing in front of the viewer through the eyeglass lens.